(a) Field of the Invention
The present invention relates to a water filter assembly for drinking water.
(b) Description of the Prior Art
Various kinds of water filters have been developed and used, generally, the water filters comprise at least one filter disposed in the front portion for filtering the larger particles and at least one activated carbon filter for absorbing chemical materials; some of the water filters further comprise "ultrafiltration film" (hereinafter refer to as UF film) or "reverse osmosis film" (hereinafter refer to as RO film) disposed after the filter for filtering micro particles, such as the bacteria. The filtered particles or bacteria are accumulated on the outside of the films.
In order that the water may flow through the filter members, a pump is required to be disposed in the beginning of the water filter assembly, a solenoid valve is provided to control the water inlet of the water filter assembly, and a pressure switch is provided to sense the inlet water pressure, when the inlet water pressure is lower than a predetermined value, the solenoid valve will be closed in order to close the water inlet to the water filter assembly, and to shut off the pump. However, when the inlet water pressure is close to the predetermined value and may sometimes higher and sometimes lower than the predetermined value, the pressure switch may be opened and closed repeatedly, the solenoid valve will also be opened and closed repeatedly within a short period of time, such condition is the so-called "jump" condition; this makes a large noise during the night.
A water flow is controlled at a predetermined time interval for cleaning the accumulated particles. However, the flushing of the water is actuated whether there are accumulated particles or not. This may waste water when no particles are accumulated.
The check valves of the water filters may become failure and water leaking may be occurred in the coupling portions of the pipes, such that water may not fully pumped into the container and such that the pump will run forever or will run intermittently and continuously, the pump will thus be easily damaged, and other serious disasters will follow.
For conventional water filters, in some circumstances, the pump will not stop and will run forever such that the pump may be damaged, and other serious disasters will follow.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional water filters.